A 90 nm CMOS LC-Tank Divide-by-3 Injection-Locked Frequency Divider With Record Locking Range

This letter proposes a wide-locking range divide-by-3 injection-locked frequency divider fabricated in the 90 nm 1P9M CMOS technology. The divider consists of an nMOS cross-coupled p-core Armstrong LC oscillator and a center-tapped inductor in series with the pMOSFETs. The pMOSFETs are used as a linear and second harmonic mixer. At the supply voltage of 1 V, the free-running frequency is from 7.84 to 8.42 GHz, the current and power consumption of the divider without buffers are 4 mA and 4 mW respectively. At the incident power of 0 dBm, the locking range is 4.28 GHz (19.8%), from the incident frequency 19.52 to 23.8 GHz.